This function is currently not documented; only the argument list is available.
This function is EXPERIMENTAL. The behaviour of this function, the name of this function, and anything else documented about this function may change without notice in a future release of PHP. Use this function at your own risk.
Draws a quadratic Bezier curve from the current point to (x,y) using (x1,y1) as the control point using relative coordinates. At the end of the command, the new current point becomes the final (x,y) coordinate pair used in the polybezier.
starting x coordinate
starting y coordinate
ending x coordinate
ending y coordinate